The Stephen Harriman Long Expedition of 1820 entered the area at the beginning of July 1820. That was the first documented exploration of the area by European or United States explorers.[5]

Much of the Denver Metro Area began to be settled as ranch land starting in 1859, but because of a lack of water in the area, it was not permanently settled until around 1870. The first legal settler of the area was Curtis H. Field, who purchased land just on the west side of Santa Fe Drive from the US government on 25 February 1870.[6]

The Highlands Ranch Mansion[7] (or "Castle Isabel") was built over a period of several years, from 1891 to 1904. The first owner of the house was Samuel Allan Long, who purchased a 40-acre homestead in northern Douglas County in 1884 and later expanded it to a 2,000-acre farm.[8] By 1891 he had built a modest farmhouse on the property and called it Rotherwood after a boyhood farm. The name "Rotherwood", a reference to a boyhood farm of Long's, was found etched above the original front door that led experts to believe so. According to the Highlands Ranch Metro District website, Long was a prominent innovator of dry land farming techniques in Colorado during the late 19th century. The mansion underwent a renovation from 2010-2012 that was funded by Shea Homes.

The Colorado Gold Rush[9] brought people to Colorado in droves during the late 19th and early 20th centuries. The city of Denver, located approximately 12 miles to the north, grew considerably during this time. However, the area remained a series of farms and ranches, and many residents would visit the town of Littleton, a few miles northward, when they needed to purchase clothing, supplies, or other items.

The Springer land was bought and sold several times throughout the 1920s and 1930s. In 1937 it was bought by Lawrence C. Phipps, Jr., who used it to raise cattle and hunt fox. After Phipps died in 1976, the land was bought by Marvin Davis, the owner of an oil company.

In 1978, a large parcel of land in unincorporated Douglas County was purchased by The Mission Viejo Company. As the suburbs of Denver expanded, the company desired to build a new planned suburb, called Highlands Ranch, in northern Douglas County, akin to its first planned development of Mission Viejo, California. Initial plans were drawn up, many of which are still being realized. These plans laid out several major streets and called for several schools and recreation centers, as well as a town center and public library. Large parcels of land were sold to private housing developers, such as Richmond Homes. As these developments appeared, they often carried their own names, creating a series of segmented neighborhoods throughout Highlands Ranch. Plans for Highlands Ranch also included a snaking "green belt" which provided for undeveloped land for recreation. The plans also allowed for a large number of public parks and bike paths.

The first homes in Highlands Ranch were built in 1981, near South Broadway Blvd. Simultaneously, the state built a new beltway through the area, SH 470, which opened in 1985. Many of the first residents of Highlands Ranch complained about the initial lack of commercial development. Residents had to drive many miles (usually into Littleton) for groceries, entertainment, or medical care. The first public school, Northridge Elementary, opened in 1982. The same year also saw the completion of the Northridge Recreation Center, an athletic club available to all Highlands Ranch homeowners. The first secondary school, Highlands Ranch Jr/Sr High School, opened in 1987. This institution became solely a high school, named Highlands Ranch High School, in 1991 with the building of nearby Cresthill Middle School. The first Highlands Ranch branch of Douglas County Libraries also opened in 1991, housed in a strip mall off Broadway and Springer Drive.

Over the next 25 years, the population of Highlands Ranch increasingly expanded. Highlands Ranch celebrated its 10th anniversary in 1991 with a population of 17,000 residents. Over the next ten years, Highlands Ranch continued to develop on a large scale. In 1997, The Mission Viejo Company was acquired by Shea Properties, which continued to expand the community. This included bringing a regional office of Lucent Technologies, and later in the same complex Avaya Communication, to the area. The year 2000 saw the opening of a much larger Highlands Ranch Library as well as the establishment of the Highlands Ranch Chamber of Commerce.

Highlands Ranch celebrated its 25th anniversary in 2006, reporting a population of 86,000 residents. Despite a growing number of local businesses, Highlands Ranch has often been labeled as the "bubble" of Denver. Many residents commute to Downtown Denver or the Denver Technological Center.

There were 34,054 households out of which 48.0% had children under the age of 18 living with them, 67.5% were married couples living together, 3.1% had a male householder with no wife present, 7.3% had a female householder with no husband present, and 22.1% were non-families. 18.2% of all households were made up of individuals, and 4.3% had someone living alone who was 65 years of age or older. The average household size was 2.84, and the average family size was 3.27.[11]

The distribution of the population by age was 32.0% under the age of 18, 5.0% from 18 to 24, 30.3% from 25 to 44, 26.1% from 45 to 64, and 6.6% who were 65 years of age or older. The median age was 36.3 years. The gender makeup of the CDP was 49.1% male and 50.9% female.[11]

The median income for a household in the CDP was $104,411, and the median income for a family was $113,944. Males had a median income of $84,067 versus $54,962 for females. The CDP's per capita income was $43,137. About 1.1% of families and 1.6% of the population were below the poverty line, including 1.4% of those under age 18 and 1.8% of those age 65 or over.[11]

As of 2013, 74.9% of the population over the age of 16 was in the labor force. 0.1% was in the armed forces, and 74.8% was in the civilian labor force with 71.1% employed and 3.7% unemployed. The occupational composition of the employed civilian labor force was: 58.2% in management, business, science, and arts; 26.4% in sales and office occupations; 8.6% in service occupations; 3.7% in production, transportation, and material moving; 3.2% in natural resources, construction, and maintenance. The three industries employing the largest percentages of the working civilian labor force were: educational services, health care, and social assistance (20.5%); professional, scientific, and management, and administrative and waste management services (16.1%); finance and insurance, and real estate and rental and leasing (12.2%).[11]

The cost of living in Highlands Ranch is above average; compared to a U.S. average of 100, the cost of living index for the community is 107.4.[16] As of 2013, the median home value in the CDP was $335,900, the median selected monthly owner cost was $2,070 for housing units with a mortgage and $533 for those without, and the median gross rent was $1,504.[11]

Highlands Ranch is an unincorporated community. As such, it is officially titled "unincorporated Douglas County" (despite the appearance of the name "Highlands Ranch" on many maps). Highlands Ranch is ultimately governed by a three-member Board of County Commissioners. These commissioners are elected from three geographic districts in Highlands Ranch. The community utilizes police protection of Douglas County, contracts with the Littleton Fire Rescue for fire protection, and all public schools are part of the Douglas County School System.

Most municipal services, such as the construction and upkeep of arterial roads, parks and open space areas, are performed by the Highlands Ranch Metro District, which is funded mostly by property taxes and state lottery funds.[17] In addition, all Highlands Ranch residents are asked to sign and follow a community covenant as dictated by the Highlands Ranch Community Association or "HRCA". This covenant places firm guidelines on such issues as housing decoration, fencing, and contribution to the area's library and recreation centers. The Highlands Ranch Community Association obtains its funding through common homeowner association fees and covenant violation fines and, for this reason, is not usually recognized as a government, but rather as a local non-profit organization.[18]